fix: comprehensive script audit - bug fixes and optimizations

- ct/invidious.sh: fix copy-paste bug (OxiCloud code in update block)
- install/invidious-install.sh: fix sed redirect, service filename mismatch
- ct/forgejo-runner.sh: fix binary download path, bump Debian to 13
- ct/authentik.sh: add -f flag to curl (fail on HTTP errors)
- ct/localagi.sh: add -f flag to curl, add installation check guard
- ct/ente.sh: fix broken install check (/var -> /opt/ente), apt-get -> apt
- ct/garmin-grafana.sh: add explicit tarball mode to fetch_and_deploy
- install/garmin-grafana-install.sh: fix local outside function, add tarball mode
- install/ente-install.sh: uncomment cleanup_lxc
- install/github-runner-install.sh: add missing , fix msg_info text
- ct/step-ca.sh: remove duplicate success message
- ct/devuan.sh, ct/ubuntu.sh: apt-get -> apt, remove duplicate msg_ok

ct/garmin-grafana.sh

@@ -40,7 +40,7 @@ function update_script() {
     cp -r /opt/garmin-grafana/.garminconnect /opt/garmin-grafana-tokens.bak
     msg_ok "Backed up Data"
 
-    CLEAN_INSTALL=1 fetch_and_deploy_gh_release "garmin-grafana" "arpanghosh8453/garmin-grafana"
+    CLEAN_INSTALL=1 fetch_and_deploy_gh_release "garmin-grafana" "arpanghosh8453/garmin-grafana" "tarball"
 
     msg_info "Restoring Data"
     cp /opt/garmin-grafana.env.bak /opt/garmin-grafana/.env